feat: add CLI debug snapshot command for one-shot instance state inspection

Adds `debug snapshot --id <int>` to query a running instance's current
attribute values and alarm states without the subscribe/stream overhead
of the debug view. Routes through ManagementActor → CommunicationService
→ site DeploymentManager → InstanceActor using the existing remote query
pattern.

src/ScadaLink.CLI/Commands/DebugCommands.cs

@@ -0,0 +1,31 @@
+using System.CommandLine;
+using System.CommandLine.Parsing;
+using ScadaLink.Commons.Messages.Management;
+
+namespace ScadaLink.CLI.Commands;
+
+public static class DebugCommands
+{
+    public static Command Build(Option<string> contactPointsOption, Option<string> formatOption)
+    {
+        var command = new Command("debug") { Description = "Runtime debugging" };
+
+        command.Add(BuildSnapshot(contactPointsOption, formatOption));
+
+        return command;
+    }
+
+    private static Command BuildSnapshot(Option<string> contactPointsOption, Option<string> formatOption)
+    {
+        var idOption = new Option<int>("--id") { Description = "Instance ID", Required = true };
+        var cmd = new Command("snapshot") { Description = "Get a point-in-time snapshot of instance attribute values and alarm states" };
+        cmd.Add(idOption);
+        cmd.SetAction(async (ParseResult result) =>
+        {
+            return await CommandHelpers.ExecuteCommandAsync(
+                result, contactPointsOption, formatOption,
+                new DebugSnapshotCommand(result.GetValue(idOption)));
+        });
+        return cmd;
+    }
+}